Polyhydramnios
Updates to Article Attributes
Polyhydramnios refers to a situation where the amniotic fluid volume is more than expected for gestational age.
It is generally defined as:
- amniotic fluid index (AFI) > 20-25
- largest fluid pocket depth (maximal vertical pocket (MVP)) greater than 8 cm 6: although some centres particularly in Australia, NZ and the UK use a cut off of 10 cm
- overall amniotic fluid volume larger than 1500-2000 cc3
- two diameter pocket (TDP) > 50 cm 2
Epidemiology
It can occur in approximately 1-1.5% of pregnancies.
Clinical presentation
The patient may clinically present as a large for dates uterus.
PathophysiologyPathology
Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders.
It is usually detected after 20 weeks (often 3rd trimester).
Causes
The potential causes of polyhydramnios are protean
-
maternal: 25-30%
- diabetes: commonly gestational diabetes
- hypertension/pre-eclampsia
- maternal congestive heart failure 8
-
fetal: 10-20%
- CNS lesions (e.g. neural tube defects): fetal CNS abnormalities tend to be the commonest out of all fetal causative associations 3
- proximal gastro-intestinal obstruction
- gastrointestinal atresia(s)
- abdominal wall defects
-
fetal intestinal volvulus
: e, e.g., fromfrom an intestinal malrotation
- fetal cervico-thoracic abnormalities
- fetal cervical masses
- thoracic masses
- congenital pulmonary airways malformation (CPAM)
- congenital high airways obstruction syndrome (CHAOS)
- congenital diaphragmatic herniation
- fetal cardiovascular anomalies
- twin pregnancy related complications
- twin-twin transfusion: occurs in recipient
- hydrops fetalis: immune and non immune
- fetal sketetal abnormalities
- reduced fetal movement
- idiopathic: 60-65%: this is a diagnosis of exclusion despite accounting for a majority of cases, also termed idiopathic polyhydramnios
Associations
- fetal macrosomia: independant of maternal diabetes 2
- mesoblastic nephroma
- Pena Shokeir syndrome
- maternal overhydration ref
Polyhydramios is associated with poor outcome if present in combination with intra uterine growth restriction (IUGR).
Classification
Some classify the severity of polyhydramnios as
- mild: single deepest pocket at 8-11 cm
- moderate: single deepest pocket at 12-15 cm
- severe: single deepest pocket >16 cm
Treatment and prognosis
The prognosis is variable dependent on associated conditions.
Management options
Usually Usually minimal or no interventional required for idiopathic mild uncomplicated cases. Options include:
- improved maternal diabetes control
- caesarian section if there is profound macrosomia
- therapeutic amniocentesis/amnioreduction
- Indomethacin 9-10
See also
-<p><strong>Polyhydramnios</strong> refers to a situation where the amniotic fluid volume is <strong>more</strong> than expected for gestational age.</p><p>It is generally defined as:</p><ul>- +<p><strong>Polyhydramnios</strong> refers to a situation where the amniotic fluid volume is more than expected for gestational age.</p><p>It is generally defined as:</p><ul>
-<li>largest fluid pocket depth (<a href="/articles/maximal-vertical-pocket-mvp">maximal vertical pocket (MVP)</a>) greater than <strong>8 </strong>cm <sup>6</sup>: although some centres particularly in Australia, NZ and the UK use a cut off of <strong>10</strong> cm</li>- +<li>largest fluid pocket depth (<a href="/articles/maximal-vertical-pocket-mvp">maximal vertical pocket (MVP)</a>) greater than 8 cm <sup>6</sup>: although some centres particularly in Australia, NZ and the UK use a cut off of 10 cm</li>
-</ul><h4>Epidemiology</h4><p>It can occur in approximately 1-1.5% of pregnancies.</p><h4>Clinical presentation</h4><p>The patient may clinically present as a <a href="/articles/large-for-dates-uterus">large for dates uterus</a>. </p><h4>Pathophysiology</h4><p>Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders. </p><p>It is usually detected after 20 weeks (often 3<sup>rd</sup> trimester).</p><h5>Causes</h5><p>The potential causes of polyhydramnios are protean</p><ul>- +</ul><h4>Epidemiology</h4><p>It can occur in approximately 1-1.5% of pregnancies.</p><h4>Clinical presentation</h4><p>The patient may clinically present as a <a href="/articles/large-for-dates-uterus">large for dates uterus</a>. </p><h4>Pathology</h4><p>Polyhydramnios occurs as a result of either increased production or decreased removal of amniotic fluid. The aetiology of polyhydramnios can be due to a vast variety of maternal and fetal disorders. </p><p>It is usually detected after 20 weeks (often 3<sup>rd</sup> trimester).</p><h5>Causes</h5><p>The potential causes of polyhydramnios are protean</p><ul>
-<li>hypertension / <a href="/articles/pre-eclampsia">pre-eclampsia</a>- +<li>hypertension/<a href="/articles/pre-eclampsia">pre-eclampsia</a>
-<a href="/articles/fetal-intestinal-volvulus">fetal intestinal volvulus</a>: e.g., from an <a href="/articles/intestinal-malrotation">intestinal malrotation</a>- +<a href="/articles/fetal-intestinal-volvulus">fetal intestinal volvulus</a>, e.g. from an <a href="/articles/intestinal-malrotation">intestinal malrotation</a>
-</ul><h4>Treatment and prognosis</h4><p>The prognosis is variable dependent on associated conditions.</p><h5>Management options</h5><p>Usually minimal or no interventional required for idiopathic mild uncomplicated cases. Options include:</p><ul>- +</ul><h4>Treatment and prognosis</h4><p>The prognosis is variable dependent on associated conditions. Usually minimal or no interventional required for idiopathic mild uncomplicated cases. Options include:</p><ul>
-<a href="/articles/therapeutic-amniocentesis">therapeutic amniocentesis</a>/<a href="/articles/amnioreduction">amnioreduction</a>- +<a href="/articles/therapeutic-amniocentesis">therapeutic amniocentesis</a> / <a href="/articles/amnioreduction">amnioreduction</a>
Sections changed:
- Gamuts